(sum-divisors) ( n -- sum )

Vocabulary

project-euler.common.private

Inputs

n

an object

Outputs

sum

an object

Definition

USING: kernel make math math.functions project-euler.common
ranges sequences ;

IN: project-euler.common.private

: (sum-divisors) ( n -- sum )
    dup sqrt >integer [1..b] [
        [ 2dup divisor? [ 2dup / + , ] [ drop ] if ] each
        dup perfect-square? [ sqrt >fixnum neg , ] [ drop ] if
    ] { } make sum ;